Pentax LX Shutter Speed Resistor Cleaning

ID: 181095

Description: The shutter speed resistor is a common point of...

Steps:

1. Winding lever cover is reverse threaded.
2. Use a piece of tape wrapped sticky side out to grip the winding lever cover. Turn clockwise to loosen and remove
3. Remove four #000 2.5 mm screws.
4. Use spanners to remove top cover retaining nut.

5. Gently remove the rubber covering around the shutter speed dial.
6. Remove three #000 1.6 mm screws.
7. Remove cover ring.
8. Installation Notes: After the camera has been fully tested, use a few dabs of contact cement to fix the rubber covering back in place.

9. Remove one #00 2.5 mm screw.
10. Remove one #00 X mm screw.
11. Lift off top cover.

12. Unhook lever spring.
13. Remove one #000 X mm screw.
14. Remove auto/manual switch lever.
15. This contact tells the camera what mode the shutter speed dial is set to: auto, manual (high speed mechanical), manual (low speed electronic), and bulb.

16. Unhook lever spring.
17. Remove slotted nut. Use isopropyl alcohol to soften thread lock if necessary.
18. Remove all components of the timing switch assembly.

19. Turn shutter speed selector to 'Auto'.
20. Turn lock lever screw clockwise to loosen. Do not remove.
21. Lock lever screw is reverse threaded.
22. Push lock lever toward the needle indicator gear.
23. Turn lock lever screw counter-clockwise to tighten.
24. Locking the needle indicator keeps it in the proper position once the shutter dial assembly is removed.

25. Unsolder two yellow wires.
26. Remove one #00 4.0 mm screw.
27. Remove one #00 2.2 mm screw.
28. Remove one #00 2.5 mm screw.
29. Remove high speed cam.
30. Installation Note: Set dial to 'Auto' before installing. After install, unlock the viewfinder indicator and check that it is showing the correct speeds in the viewfinder as the dial is turned.

31. Rotate the speed dial until the feeler contacts are visible in the gap.
32. Spray with a plastic safe contact cleaner and rotate back and forth.
33. Check the resistor values at the slow speed settings. They should range from around 9 kΩ (at 60) to 200 kΩ (at 4s) with no dead spots.
34. Clean the seat for the high speed cam with isopropyl alcohol. A narrow cotton bud or a floss pick work well.
35. Lubricate the high speed cam seat with shutter oil.